Control mechanism for belt manlifts



Dec. 2, 1958 H. DEVERELI. 2,862,577

CONTROL MECHANISM FOR BELT MANLiFTS 2 Sheds-Sheet 1 Filed May 16, 1957 INVENTORQ HARRY DEVERELL i I v ATTORNEY Dec. 2, 1958 CONTROL Filed May 16, 1957 H. DEVERELL MECHANISM FOR BELT MANLIFTS 2 Sheets-Sheet 2 POWER LINES REVERSE PHASE REL AY MAGNETIC.

STARTER AGNETIC CONTACTOR RESET JL LlMlT 6WITCH ES INVENTOR.

HARRY DEVERE LL ATTORNEY CONTROL MECHANISM. OR BELT MANLIFTS Harry Devere'll, Millburn, N. J. Application May 16, 1951, SerialNo. 659,603

1 Claim. (Cl. 187-44) This invention relates in general. tosocalled belt man- .lifts that -.compr s n e dles belt m unt on pu y on a ve t a t m h t sua y ex nds thr ugh p ning in a plurality of floors in a building with the reaches of the belt vertically disposed and having connected thereto steps upon any one .ofwhich a man may step from one limit witches are usually inc uded n c c t w t the main swit nd emete torautemate y steppi the meter in case a m n ails. to .1eav -th st pt t the p p a the' pp r end and ow rud f th f m t y 'tep ev u jury to he m n- H wever. the m in wi h the s a a f the mo because whe ne of: said l mit swi ches is p rate to does not exclusively con tep t e-mo or, the motor will resume oper tion when the man resets the limit switch. Consequently, if; another man was on-the. manlift :hemight be. caused to fall by the sudden starting .of the motor and the belt.-

A. prime .obiectof the :presenttinyention is to provide a control mechanism which shall embody novel and ZiIHPIOYQd features ofeonstruction to overcome this diffivculty with the, known typesof manlifts and to makeit impossible to start the motor except by operation of the main switch. Inother words theinvention contemplates a control mechanismrwherein Zthe starting of the motor shall :be controlled exclusively .-by the main :switch which in turn shall vbe actuated by .anovel and improved actuating mechanism including .a control rope for .each reach of the-manlift belt and novel means for transmitting motion from the control ropes to-the switch.

Another .object of theinvention is to provide such a control mechanism wherein the means fort'ransmitting motion to thefmain switch shallautomatically return to a neutral position after-eachoperationaof-the switch so that even if a limit switch is actuated-and then reset, the belt can :not be started until the appropriatecontrol rope has been pulled in the right direction.

Other objects, advantages and results of the invention will be brought out :by the following description in conjunction with the accompanying drawingsin which:

Figure l is a fragmentary side elevation of theupper portion: of a belt-manlifthaving a' e'ontrol mechanism -einbodyingnhe -i-nventionand showing the ma-nlift associated with several floors of a building with portions broken away;

Figure 2 is a similar view of the lower portion of the manlift and control mechanism;

Figure 3 is a fragmentary front elevation of the upper portion of the manlift shown in Figure 1;

United States atent Figure 4 is an enlarged fragmentary horizontal sectional view approximately on the plane of the line 4-4 of Figure 1, showing one of the limit switches;

Figure 5 is an elevation of the portion of the elevator and the limit switch shown in Figure -4 with the switch in normal'closed position;

Figure 6 is a view similar to Figure 5 showing the switch actuated into open position;

Figure 7 is an enlarged schematic composite side elevational and sectional view of the control mechanism embodying the inventiomand Figure 8 is a schematic wiring diagram of one possible electrical circuit including themain switch in accordance with the invention.

Specifically describing the illustrated embodiment of the invention, the manlift includes ,a vertical frame A having a base portion B thatis mounted on any suitable support, such as the basementvfloor of a building, with the frame extending vertically through openings C in floors of a building or platforms of an elevator structure. A pulley E is mounted at the lower end of the frame on a shaftel which is journaled in suitable bearings 2, and a similar pulley F is mounted at the upper end of the frame ona shaft 3 that is journaled in bearings 4, and a flexible wide belt G runs over said pulleys with its reaches disposed vertically. The belt is driven in known manner .by an electric motor and reduction .gear combination H, the output shaft of which is connected to the shaft 3 of the pulley F.

Secured .to thebelt in the usual manner in equidistantly spaced relation longitudinally of the belt are a plurality of steps I, each of which includes a frame 6 having two rollers 7 journaled thereon in spaced relation longitudinally of the belt at each end of the step, said rollers at the ends of the step running in corresponding vertical channel bars 8 that form parts of the frame A. Each step also has oppositely facing treads 9-so that one tread faces upwardly when the step is-moving upwardly, while the other tread faces upwardly when the step is moving downwardly. A handhold 10 is secured to the belt above each-step.

Above the top floor or landing and below the upper pulley-F, at least one and preferably two limit switches N'are provided to automatically stop the belt if a person remains on the step after the step-has passed said topmost floor or landing, and a similar-limit switch 0 is provided immediately below-the lowermost floor or landing D to stop the beltif a person remains on the step at said floor or landing. These limit switches are of known construction and include an actua-t-ing lever P connected to a spring biased toggle switch contact block so that the switch is normally in closed position with the operating lever P abutting a-section 11 of one flange of a channel bar 8 which ishinged at 12 on abracket '13 secured to the channel bar,-which hinge section 11 is normally influenced by a spring 14 into normal position in alignment with the flange of the channel bar as shown in Figure 5, a stop-plate '15 on the hinge section-11 being provided to limit movement ofthehinge section under action of the spring. When the lower step roller '7 in the corresponding frarn'e bar 8 engages the hinge section 11 with a personstanding on the step,- thebeltG is slightly flexed {and said roller pushes the hinge section outwardly to actuate the switch into open position as shown in Figure 6 and thereby stop the motor and the movement of the belt. The switch will remain in this open position until it is manually reset.

The structure so far described is in general old and no claim to novelty is made thereon. An important feature of the invention is the provision of a control mechanism including a main switch I so that the motor relay in the usual manner.

can not be started after such automatic operation of said limit switches, except by manual actuation of the main switch I which is connected in circuit with the limit switches, motor starting mechanism and a brake, as hereinafter described, and the main switch can be operated only by a pull on'one of the control ropes K and L.

In accordance with the invention, a lever or rocker 16 is pivotally mounted at 17 at the upper end of the frame A in closely spaced relation to one edge of the belt G and a similar lever or rocker 18 is pivotally mounted at 19 'at the lower end of the frame. One control rope K has its ends adjustably connected at 20 to the corresponding ends of the upper and lower rockers, respectively, while the ends of the other control rope L are adjustably connected at 21 to the other ends of said rockers so that the control ropes are in closely spaced parallel relation to one edge of the belt G. The upper rocker 16 has at least one switch actuating arm 22 for actuating the main switch I and this operating arm is normally held in a neutral position by identical combined spring and dash pot devices M. As shown, each of these devices includes a vertically disposed cylinder 23 rigidly mounted on a bar 24 forming a part of the frarne A. In the cylinder is slidably mounted a piston 25 that has a rod 26 connected to one end thereof and projecting through an opening 27 in one end of the cylinder;

and said piston rod has a flexible or lost motion connec tion 28 with one end of the rocker. As shown, this connection is a chain, but other types of connections could be used. Preferably one end of the chain is adjustably connected at 29 to the rocker. A spring 30 interposed between the piston and one end of the cylinder, normally biases the piston toward the other end of the cylinder and exerts an upward pull on the rocker, and an air vent 31 controlled by a valve 32 is provided in the second mentioned end of the cylinder to retard the movement of the piston under the influence of the spring.

Normally the parts are so adjusted that the springs 30 will hold therocker 16 with its arm 22 in the neutral position shown in Figures 1 and 7. Obviously a pull ,on either control rope K or L in either direction will swing the rocker and the arm 22 in one direction or the other, and the springs will return the rocker and its arm automatically to the neutral position. Movement of the 'arm 22 in one direction will actuate the main switch I to start the motor and belt, while movement of the arm in the opposite direction will stop the motor and belt.

The main switch may be of any suitable construction and there might be more than one switch. The switch will be connected in circuit with the motor, the usual magnetic contactors, magnetic starters and reverse phase Figure 8 is a schematic wiring diagram of one possible circuit. For the purpose of simply explaining the principles of the invention, the main switch is shown as including a pair of start contact points and another pair of stop contact points. One of the start contact points 33 may be fixed in a suitable casing while the other start contact point 34 is mounted .on a movable insulated carrier 35. One of the stop the manlift, he will exert a pull on the adjacent pull the belt.

rope K or L in the direction opposite that in which he desires to travel and whereupon the rocker arm 22 will be swung to close the start switch and simultaneously open the stop switch, and when the pull rope is released the springs 30 will return the rocker arm to its neutral position. When the manlift belt is moving with a person on the step and it is desired to stop the belt, the adjacent control rope is simply gripped by the person and the movement of his body with the belt will exert a pull on the control rope and swing the rocker arm 22 from its neutral position in the direction to close the stop switch and open the start switch and thereby stop Then, upon release of the control rope the springs 30 will return the rocker arm 22 to its neutral position.

Preferably, all of the switch contacts will be arranged in a common housing with the operating fingers 38 projecting therefrom as shown in Figure 7.

The now preferred embodiment of the invention has been shown and described, but it will be understood by those skilled in the art that the invention may be embodied in other structural details and that different types of switches and other electrical apparatus may be ,utilized within the spirit and scope of the invention.

What I claim is:

in a belt manlift, the combination of a vertical frame having belt pulleys journaled thereon in vertically spaced relation and an endless belt carrying steps running over said pulleys and having two vertical reaches, driving 'means for said belt including an electrical motor and a speed-reducing driving connection between said motor and one of said pulleys, control mechanism for starting and stopping said motor including a main switch having start contact points and stop contact points and spaced apart operating fingers therefor, a control rope in closely spaced parallel relation to each reach of the belt, an actuating element movably mounted on said frame and normally disposed between said fingers in neutral spaced relation to both thereof and connected to both of said control ropes so that a pull on either control rope in the direction of movement of the corresponding belt reach will move said actuating element in one direction into engagement with one of said fingers and actuate said switch to stop said motor, while a pull on either rope in the opposite direction will move said actuating element in the other direction into engagement with the other finger and actuate the switch to start said motor, and yieldable means normally biasing said actuating element into said neutral position after each said movement of the actuating element, said control mechanism including a rocker lever pivoted intermediate its ends adjacent each of said pulleys, said control ropes being connected to the corresponding ends of said rocker levers, said actuating element comprising an arm projecting from one of said rocker levers, and the last-named means including a cylinder mounted on said frame adjacent each end of one of said levers, a piston in each cylinder having a rod extending from one end of the cylinder and flexibly connected to the corresponding end of said lever, a spring normally biasing said piston toward the other end of said cylinder,

and a valve-controlled vent in the second-mentioned end of the cylinder.

References Cited in the file of this patent UNITED STATES; PATENTS," 

